1. Field of the Invention
The present invention relates to a method of forming a pattern, and more particularly, to a method of forming a fine pattern, in which a nanopattern having a pattern dimension of 1 μm or less can be repeatedly reproduced, simply and easily, and to a method of manufacturing a nitride-based semiconductor light emitting device using the method of forming a fine pattern.
2. Description of the Related Art
A method of forming a pattern using a conventional light lithographic method such as, for example, g-Line lithography using light having a wavelength of 436 nm, i-line lithography using ultraviolet (“UV”) light at a wavelength of 365 nm, or deep-UV lithography using light having imaging wavelengths of 248 nm or 193 nm, includes multilevel operations such as forming a photoresist layer on a substrate, a soft baking process, a develop process and so on. Since the method uses light, it is difficult to form a pattern having a pattern dimension of 1 μm or less. Accordingly, various nanopatterning methods have been introduced. Among these, the two most promising methods at present are Extreme ultraviolet (“EUV”) lithography and Electron beam lithography.
EUV lithography is an imaging method using very short wavelength ultraviolet light of e.g., 11-14 nm, which may be used to form a fine patterned surface relief grating on a substrate. EUV lithography uses conceptually similar equipment for effecting the imaging as those used in conventional light lithographic methods as described hereinabove are also used in EUV lithography. However, a mask and a lens as used in conventional light lithographic methods are not useful in EUV lithography due to the smaller feature sizes which require improved mask technology, and the high absorbance of conventional lens materials at EUV wavelengths. Accordingly, in place of a lens, EUV lithography uses reflective optics based on higher-order reflective materials (such as, e.g., molybdenum silicide layered reflective lenses), and consequently the optics used in EUV lithography are not trivial in their construction or necessarily small-sized.
Electron beam (“e-beam”) lithography is another method in which a pattern is formed by irradiating an electron beam directly on a substrate. A finer pattern can be formed by e-beam lithography when compared with that obtained using EUV lithography. However, since Electron beam lithography has increased manufacturing costs and is difficult to achieve accurate results, Electron beam lithography is not commonly used in a method of manufacturing an element.
In addition to the methods described above, other non-optical or irradiative methods have been examined such as, for example, a Nano imprint method in which a pattern is formed using a nano-size mold, a self-assembly method using self-assemble properties of the molecules; a molecular or atomic manipulation in which a pattern is formed by manipulating directly a molecule or an atom; or the like. However, for these methods of forming patterns, materials used are limited and reproducibility is poor. In particular, it is difficult to form a pattern having a pattern dimension of 1 μm or less.